From d99e0a7c979a1ee96b2eea1b9011d5bce375289a Mon Sep 17 00:00:00 2001
From: Michael Kret <88898367+michael-radency@users.noreply.github.com>
Date: Thu, 21 Nov 2024 11:16:10 +0200
Subject: [PATCH] fix: CodeNodeEditor walk  cannot read properties of null
 (#11129)

Co-authored-by: Elias Meire <elias@meire.dev>
---
 .../components/CodeNodeEditor/utils.test.ts   | 44 +++++++++++++++++++
 .../src/components/CodeNodeEditor/utils.ts    | 30 +++++++------
 2 files changed, 61 insertions(+), 13 deletions(-)
 create mode 100644 packages/editor-ui/src/components/CodeNodeEditor/utils.test.ts

diff --git a/packages/editor-ui/src/components/CodeNodeEditor/utils.test.ts b/packages/editor-ui/src/components/CodeNodeEditor/utils.test.ts
new file mode 100644
index 0000000000..a821403e4c
--- /dev/null
+++ b/packages/editor-ui/src/components/CodeNodeEditor/utils.test.ts
@@ -0,0 +1,44 @@
+import * as esprima from 'esprima-next';
+import { walk } from './utils';
+
+describe('CodeNodeEditor utils', () => {
+	describe('walk', () => {
+		it('should find the correct syntax nodes', () => {
+			const code = `const x = 'a'
+function f(arg) {
+   arg['b'] = 1
+   return arg
+}
+
+const y = f({ a: 'c' })
+`;
+			const program = esprima.parse(code);
+			const stringLiterals = walk(
+				program,
+				(node) => node.type === esprima.Syntax.Literal && typeof node.value === 'string',
+			);
+			expect(stringLiterals).toEqual([
+				new esprima.Literal('a', "'a'"),
+				new esprima.Literal('b', "'b'"),
+				new esprima.Literal('c', "'c'"),
+			]);
+		});
+
+		it('should handle null syntax nodes', () => {
+			// ,, in [1,,2] results in a `null` ArrayExpressionElement
+			const code = 'const fn = () => [1,,2]';
+			const program = esprima.parse(code);
+			const arrayExpressions = walk(
+				program,
+				(node) => node.type === esprima.Syntax.ArrayExpression,
+			);
+			expect(arrayExpressions).toEqual([
+				new esprima.ArrayExpression([
+					new esprima.Literal(1, '1'),
+					null,
+					new esprima.Literal(2, '2'),
+				]),
+			]);
+		});
+	});
+});
diff --git a/packages/editor-ui/src/components/CodeNodeEditor/utils.ts b/packages/editor-ui/src/components/CodeNodeEditor/utils.ts
index d37bc87648..e75dfa927a 100644
--- a/packages/editor-ui/src/components/CodeNodeEditor/utils.ts
+++ b/packages/editor-ui/src/components/CodeNodeEditor/utils.ts
@@ -1,29 +1,33 @@
-import type * as esprima from 'esprima-next';
+import * as esprima from 'esprima-next';
 import type { Completion } from '@codemirror/autocomplete';
-import type { Node } from 'estree';
 import type { RangeNode } from './types';
 import { sanitizeHtml } from '@/utils/htmlUtils';
+import type { Node } from 'estree';
 
 export function walk<T extends RangeNode>(
 	node: Node | esprima.Program,
 	test: (node: Node) => boolean,
 	found: Node[] = [],
 ) {
-	// @ts-ignore
-	if (test(node)) found.push(node);
+	const isProgram = node.type === esprima.Syntax.Program;
+	if (!isProgram && test(node)) found.push(node);
 
-	for (const key in node) {
-		if (!(key in node)) continue;
+	if (isProgram) {
+		node.body.forEach((n) => walk(n as Node, test, found));
+	} else {
+		for (const key in node) {
+			if (!(key in node)) continue;
 
-		// @ts-ignore
-		const child = node[key];
+			// @ts-expect-error Node is not string indexable, but it has many possible properties
+			const child = node[key];
 
-		if (child === null || typeof child !== 'object') continue;
+			if (child === null || typeof child !== 'object') continue;
 
-		if (Array.isArray(child)) {
-			child.forEach((node) => walk(node, test, found));
-		} else {
-			walk(child, test, found);
+			if (Array.isArray(child)) {
+				child.filter(Boolean).forEach((n) => walk(n, test, found));
+			} else {
+				walk(child, test, found);
+			}
 		}
 	}